Background: During the COVID-19 epidemic, many neonates were involved, but they had fewer complications and deaths than adults. Therefore, in this review study, we investigated the immune mechanisms of neonates in response to COVID-19.
Methods: We reviewed articles that evaluated the immune system, COVID-19, or SARS-COV2 in neonates. We searched the databases of Google Scholar, PubMed, Scopus, Web of Sciences, SciELO, and CNKI databases published up to December 2022.
Results: There are different immune mechanisms in response to COVID-19 in infants, which lead to a different response to COVID-19 compared to adults. The important mechanisms include lower expression of ACE2 receptor, abundant of naive T cells, absence of cytokine storm, abundant of immunosuppressive cells, less inflammatory reactions, breastmilk secretory IgA, transfer of IgG through the placenta, and absence of chronic comorbidities. Also, in comparison with pediatrics multisystem inflammatory syndrome in children (MIS‐C) doesn’t observe in neonates.
Conclusion: The exact immune mechanisms in response to COVID-19 in infants have not yet been discovered, but knowing the exact mechanisms can be effective in future treatments, the production of effective vaccines, and other viral treatments, so there is a need for more investigations in this field.